Welcome, Donald. OK, just to clarify, a T Coupe and T-Bucket are not the same and the "Bucket" is not a cut up coupe. The Bucket is a roadster and it may be built with or without the "turtle deck" (the trunk section) as it is removeable. The Model-T coupe is dimensionally different, has a roof of course, and the trunk is not removeable. The only interchangeable part of the original bodies is the firewall. Of course, you could make a roadster out of a coupe by cutting off the roof.

FYI - The 1926 and '27 bodies are identical. If you plan on using a fiberglass body, you may have to settle for a roadster. Someone else may know better, but I've never seen fiberglass T coupe bodies...